(1) Field of the Invention
This invention relates to a method of sealing fine cracks and cavities in a pipeline for distributing gas, water or the like and at the same time internally coating the pipeline, and in particular to a method of internally coating or sealing such a pipeline for fuel gases by using a foamed sealant.
(2) Description of the Prior Art
The method of sealing fine cracks and cavities in a pipeline and at the same time internally coating the pipeline with a foamed sealant is already known and is used when leakage has occurred or is likely to occur in pipelines, particularly those for distributing gas such as fuel gas. The known method comprises the steps of supplying and filling a pipeline with a foamed sealant of the aqueous emulsion type whereby the sealant penetrates the leaking point, passing air through the pipeline to discharge an excess amount of the sealant, the rest of the sealant remaining in tubular form extending axially of the pipeline and adhering to the interior wall thereof, and finally allowing the residual, tubular sealant to cure.
This method is far more efficient than the old method of replacing a leaking pipeline portion or filling the pipeling with a sealant in liquid state. However, it is required today to shorten the time for repair work.